Problem: $ { {-4} \times \left[\begin{array}{rrr}{4} & {-1} & {4} \\ {-1} & {0} & {4}\end{array}\right] = {?} } $
To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-4}\times{4} & {-4}\times{-1} & {-4}\times{4} \\ {-4}\times{-1} & {-4}\times{0} & {-4}\times{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-16} & {4} & {-16} \\ {4} & {0} & {-16}\end{array}\right]}$